After spending (it turned out, wasting!) a bit of time tracing this family through snippets of volumes like "The Hanbury Family" (1916) by A. Audrey Locke, in the process finding a link to the Lloyds of Dolobran in BLG 1847, I eventually found that these Hanburys appear under "Hill, formerly Hanbury, of Holfield Grange" in BLG 1965, and connect to the family of the Barons Sudeley (details to follow).
Christopher Osgood Philip Hanbury educ. Millfield and R.A.C. Cirencester; only (posthumous) s. of Osgood Philip Villiers Hanbury (1917-1943), Sq.Ldr R.A.F., D.S.O., D.F.C. & bar and (m. 1943) Patricia, dau. of Col Charles Cecil Harman, D.S.O., of Crossdrum, co. Meath [BLG 1965 cross-references "Burke's L.G. of Ireland"].
O. P. V. Hanbury only s. of Maj. Philip Hanbury (1879-1955), 3rd Battalion, Green Howards, and (m. 1913) Dorothy Maude, dau. of Henry Villiers Margary.
P. Hanbury s. of Ernest Osgood Hanbury (1852-1927) and (m. 1st, 1875, div. 1890) Clara Martha (d. 1917), dau. of John Dunstan Whitehead, of Yatton, Somerset.
E. O. Hanbury 5th s. of Philip Hanbury (1802-1878), of Redhill, Surrey, J.P., City banker and (m. 1843) Elizabeth Christina, elder dau. and co-heir of Simon James Charles, Baron Collat D'Escury, of Rotterdam, by his wife Clotilda Elizabeth, only dau. of Sir Robert Barclay, 8th Bt, of Pierston.
P. Hanbury 6th s. of Osgood Hanbury (1765-1852), of Holfield Grange, nr Coggeshall, Essex, City banker, and (m. 1789) Susannah Willet, dau. of John Barclay, City banker. Their eldest son, Osgood, was ancestor of the senior line of the family treated in this pedigree, and the second, Robert, was of Poles, the ancestor of "Hanbury of Drumstinchall, formerly of Poles" and the branch of that family "Hanbury of Hitcham and Melgate" (both also treated in BLG 1965).
Osgood Hanbury s. of Osgood Hanbury, of Holfield Grange, and (m. 1757) Mary, eldest dau. of Sampson Lloyd, of Birmingham, banker [this the connection to the Dolobran Lloyds, as treated in BLG 1847 etc].
Osgood Hanbury s. of John Hanbury, of Llanvihangel, and Hannah, dau. of Obadiah Osgood, of Holfield Grange. Here, the pedigree directs to "Hanbury, formerly of Kingston Maurward" (in BLG 1965); John Hanbury s. of Charles Hanbury (1677-1735), of Panteague, Monmouths., M.D. and (m. 1st) Grace, dau. of - Brace, of Yarnall, Worcs., and widow of Jenkinson Beadles, of Llanvihangel-Ysterne-Llewerne, Monmouths.
Charles Hanbury elder s. of Richard Hanbury (1647-1714), of Panteague and (m. 2nd) Mary, dau. of -
Richard Hanbury s. of Richard Hanbury (1610-1695), of Panteague, "one of the earliest members of the Society of Friends" and (m. 2nd) Elizabeth, dau. of -
Richard Hanbury eldest s. of Philip Hanbury (b. 1582), of Elmley Lovett, Worcs. afterwards of Trevithin, Monmouths. and Alicia (d. 1630), dau. of -
Philip Hanbury 2nd s. of Richard Hanbury, of Elmley Lovett; here the pedigree directs to "Burke's Peerage, SUDELEY, B.", but unfortunately I don't have access to my BP 2003 at the moment so can't find the exact link. Stirnet, citing the BP 1934 Sudeley entry, shows Richard Hanbury's elder son, John, of Pakenham, Sheriff of Worcester (d. 1659) as ancestor of the 1st Lord Sudeley. The pedigree traces back to the 1200s, via a Henry de Hanbury, d. c. 1353, Lord Chief Justice in Ireland. Thepeerage.com, citing BP 2003, seems to corroborate all the above, but goes back to a Guy de Hanburi, of Hanbury, Worcs., fl. c. 1155/89.